Five U.S. soldiers were killed Thursday, and seven others were wounded, when a massive roadside bomb exploded while they were on patrol in southern Baghdad. The deaths came as the Pentagon wrapped up the deadliest three-month period for U.S. troops in Iraq since the 2003 invasion; 329 U.S. troops have been killed since April.

That grim statistic comes despite the fact that all of the U.S. troops sent to Iraq as part of the U.S. military's so-called "surge" strategy are now in place. The Pentagon says there's statistical evidence to show violence is down in Baghdad. Even so, overall violence in Iraq is at a three-year high.

Still, the commander of U.S. forces in Baghdad, Maj. Gen. Joseph F. Fil Jr., sees signs that his efforts to control violence in the capital are working.

"I see progress," Fil told reporters at a news conference Friday, "a steady progress in every neighborhood we've cleared and then established a full-time presence."

The Pentagon's 'New' Strategy

Fil is talking about a strategy called "clear, hold and retain." The White House and Pentagon are touting it as the new Iraq strategy.

Basically, U.S. troops go into a neighborhood and "clear" it. This usually involves a fight. Once it's cleared of insurgents, the neighborhood is then "held" by other U.S. troops for a few days or weeks. At that point, the troops hand the area over to Iraqi soldiers who "retain" the area permanently.

While the strategy of "clearing and holding" is considered new by some strategists in the Pentagon, it's not. It was used during the last few years of the Vietnam War — and it has also been employed before in Iraq. Last summer, during "Operation Together Forward," Gen. George Casey, then the top U.S. ground commander in Iraq, used the same language.

The biggest proponent of the strategy is a retired Australian army officer named David Kilcullen, a counterinsurgency expert and senior adviser to Gen. David Petraeus. Kilcullen writes about the progress of the strategy on a blog called called smallwarsjournal.com.

A Question of Time

Most military experts believe the strategy is sound. The only problem is that it takes time — and that's a commodity in short supply for U.S. commanders.

With nearly 60 percent of the American public supporting a rapid drawdown of U.S. forces in Iraq, there's very little chance that the strategy will succeed by September, when Congress expects a full assessment from Petraeus on how the "surge" is faring.

The Pentagon doesn't want to measure success or failure in Iraq based on U.S. and Iraqi body counts. Though few Pentagon officials will admit it, this is a departure from the way they measured progress in the past — what the Pentagon calls a "metric."

Gen. Peter Pace, the outgoing chairman of the Joint Chiefs of Staff, told reporters at the Pentagon Friday, "If you tell the enemy that what's important to you is the number of bombs you set off, guess what the enemy's going to do? He's going to set up more bombs. So [body counts are] a self-defeating approach to tracking results of what you're doing."

Pace wants progress to be measured by Iraqi perceptions about their current and future condition.

Pace says he wants these questions asked: "Do the Iraqi people feel better about today than they did about yesterday? And do they think tomorrow is going to be better than today? If the answer to those questions is yes, then we're on the right path."

The latest poll taken in Iraq shows that 57 percent of Iraqis believe life is no better since the invasion, and may be even worse. Nearly 60 percent believe it will remain the same or get worse five years from now.